Kinosternon flavescensAgassiz, 1857

Yellow Mud Turtle

Photograph by Fishes of Texas team, CC BY-SA, via iNaturalist

A day-active, omnivorous turtle from the Nearctic region, reaching 165 mm nose to tail.

Reptilia › Testudines › Kinosternidae › Kinosternon

Grows to: 165mm; greatest recorded
Eats: Omnivorous
Active: Diurnal
Lives up to: 40years

Body length across Kinosternidae

Longer than 52% of all species in Kinosternidae anyone has measured.

52% of 27 species are smaller48% larger

114 mmthe whole family, smallest to largest380 mm

The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 114 to 380 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.

What is known

28 sourced facts, each taken from a named scientific dataset. How to read these.

Cited from a dataset unless a row is marked otherwise.

Standing in the world

Conservation status: Least Concern

The animal itself

Colour on the back: Brown, Yellow
Pattern on the back: Uniform
Pupil: Round
Venomous: No
Fangs: None
Longest recorded life: 40years
Body temperature when active · measured in the wild: 24.9°C77 °F
Body temp in the wild · mean, when active: 22–27.8°C72–82 °F

Size

Length nose to tail · greatest recorded: 165mm6.5 in
Body mass · greatestcomputed: 733g1.6 lb
Body mass at hatching: 4.84g0.17 oz

How it lives

Diet: Omnivorous
How it hunts: Active foraging
Active: Diurnal
Where it lives: Arboreal, saxicolous, terrestrial
Habitat: Grassland, Wetlands
Region: Nearctic
Highest it lives · above sea level: 1066m

Breeding

Reproduction: Oviparous
Sex decided by: Temperature
Average clutch: 4.78eggs
Eggs or young per clutch: 1–9eggs
Clutches in a year: 3per year

Naming and history

Subspecies: No
Described by: Agassiz
Moved to another genus · since it was first described: Yes
Described in: 1857

Keeping one

Active animals measured in the wild averaged 77 °F (24.9 °C).

Mean body temperature of active individuals measured in nature. A measurement of the animal, not a setting for a thermostat.

Feeding

A prey item should be no wider than the space between the animal's eyes.

Widely used across reptile husbandry references. The stated reason is that the gap approximates the width of the throat, so wider prey is associated with impaction. This is established practice, not a measurement.

69kJ per day

Worked out for an animal of 733 g, the heaviest recorded for Yellow Mud Turtle — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.

An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.

What nobody knows

These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.

— Still living
— Length snout to vent · greatest recorded
— Length snout to vent · adult female mean
— Length snout to vent · adult male mean
— Length snout to vent · adult mean
— Female length · mean, nose to tail
— Length nose to tail · adult male mean
— Length nose to tail · adult mean
— Shell length, front to back · greatest recorded
— Largest female · snout to vent
— Largest male · snout to vent
— Largest female · shell length
— Largest male · shell length
— Hatchling length · snout to vent
— Hatchling length · nose to tail
— Largest juvenile · snout to vent
— Largest juvenile · shell length
— Egg length
— Egg width
— Body mass · a typical adult
— Body mass · adult female, mean
— Preferred body temperature · chosen in a laboratory gradient
— Eats arthropods
— Eats vertebrates
— Eats plant matter
— How the young develop
— Gestation or incubation
— Mean clutch · smallest reported
— Mean clutch · largest reported
— Clutches a year · fewest
— Clutches a year · most
— First breeds from · youngest recorded
— First breeds by · oldest recorded
— Hatchling length · smallest recorded
— Hatchling length · largest recorded
— Age at first breeding · female
— Mature from · youngest recorded
— Mature by · oldest recorded
— Size at maturity · smallest recorded
— Size at maturity · largest recorded
— Limbs
— Status assessed · the year the Red List last looked
— Population trend
— Red List criteria
— Biome
— Active season · shortest recorded
— Active season · longest recorded
— Density · lowest recorded
— Density · highest recorded
— Home range · largest recorded
— Suborder
— Infraorder
— Type locality
— Active in
— Mainland or island
— Lowest it lives · above sea level
— Range size

Others in Kinosternidae

Take this data

Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.

This species as JSON · the whole dataset

Cite this page

The Reptile & Amphibian Encyclopedia (2026). Kinosternon flavescens. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/kinosternon-flavescens

@misc{kinosternon_flavescens_2026,
  title  = {Kinosternon flavescens},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/kinosternon-flavescens}
}

Sources

Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
Catalogue of Life (dataset 3LR), used under CC BY.
Moura, M. R. et al. TetrapodTraits: a database of 33,281 tetrapod species. Used under CC BY 4.0. Observed values only; this encyclopedia does not publish its imputed predictions.